This invention relates to a nozzle with guiding devices. A nozzle of this type is used for example in a gas turbine, in particular an aircraft engine, or in a burner, an ejector or a mixing nozzle of a process engineering system.
During take-off of an aircraft, the propulsive jet represents a considerable source of sound. Contributing to the generation of sound are stable and coherent swirl structures that form in the shear layers of the free jet. Numerous passive and active measures are known for reducing the jet noise.
The generic EP 2 072 793 A2 describes a nozzle with guiding elements, on the rim of which nozzle diffuser-type and nozzle-type guiding elements are alternating provided. The guiding elements form here trapezoids alternately converging and diverging in the flow direction. These guiding elements impart a swirl to the outflowing medium at the nozzle rim where the outflowing medium meets the surrounding medium. The resultant axial and radial swirls weaken the stable, coherent and noise-generating swirl structures and thus lead to reduced noise generation in the propulsive jet.
There is an ongoing need to provide a further reduction of the jet noise from aircraft while at the same time keeping aerodynamic losses low.